"The author of this piece, Randy Simmons, is the Charles G. Koch professor of political economy at Utah State University. He's also a senior fellow at the Koch- and ExxonMobil-funded Property and Environment Research Center. These ties to the oil industry weren't originally disclosed in this piece. "
While Simmons may be a senior fellow at the Property and Environment Research Center, according to a blog post by Erik Wemple on the Washington Post website, citing an interview with Simmons himself, he is no longer a Koch Professor.
Although the Newsweek correction links to a Linkedin page indicating that Simmons is currently a Koch Professor, it would appear that the Washington Post has confirmed otherwise.
Still, even though the Newsweek correction may only be half right it's far from being entirely wrong.